well you could get s single in dual outlet muffler and run your own pipe. or the more expensive way is to do the srt exhaust conversion. I have a full custom exhaust from the heads back on my 3.7. you should check that out for ideas.

It would be quite expensive to put a custom true dual setup on a WK. It can be done though, if you want to spend the $$$. You can do like Jeff said, but why, unless you just want two pipes out the back? It's easier and less expensive to go with a single 3 in. system all the way back. If you're after performance and economy, you should address the crappy 5.7 exhaust manifolds first. Jeff has headers on his 3.7 and I have custom headers and a 3 in. single straight through catback on my 5.7 and, believe me it makes a world of difference over the stock setup. If you're just after sound, stick with the stock setup and a different muffler. Be aware though that, if you go too loud, you'll get a substantial drone when the MDS is active.

Here's a couple threads I did regarding the 5.7 exhaust. You can see how bad the stock system is and the big differences when changing over to a better header/manifold.

It would be quite expensive to put a custom true dual setup on a WK. It can be done though, if you want to spend the $$$. You can do like Jeff said, but why, unless you just want two pipes out the back? It's easier and less expensive to go with a single 3 in. system all the way back. If you're after performance and economy, you should address the crappy 5.7 exhaust manifolds first. Jeff has headers on his 3.7 and I have custom headers and a 3 in. single straight through catback on my 5.7 and, believe me it makes a world of difference over the stock setup. If you're just after sound, stick with the stock setup and a different muffler. Be aware though that, if you go too loud, you'll get a substantial drone when the MDS is active.

Here's a couple threads I did regarding the 5.7 exhaust. You can see how bad the stock system is and the big differences when changing over to a better header/manifold.

I agree. Open up the manifolds bys using srt ones or a set of headers. You would also need to do the srt mid pipes if you go with the srt manifolds. As jeep has said, im running jba short tubes on mine. Made a huge world of difference. I picked up 3 tenths in the 8th mile just swapping them out. It pulls hard from 3k to redline now.

While on the subject....I think I may have a small exhaust leak on the left side anyway...if I am driving with the window down, if im on the gas at all I can hear it coming from under the drivers side....its not a knock or ping....more of a hiss type sound.
Got under her and checked exhaust back to the cat....no holes although one of the gaskets looks suspect.....but im thinking it could be the exhaust manifold rather than the exhaust or gasket.

While on the subject....I think I may have a small exhaust leak on the left side anyway...if I am driving with the window down, if im on the gas at all I can hear it coming from under the drivers side....its not a knock or ping....more of a hiss type sound.
Got under her and checked exhaust back to the cat....no holes although one of the gaskets looks suspect.....but im thinking it could be the exhaust manifold rather than the exhaust or gasket.

So, I have an 05 5.7. What is needed to fit SRT8 manifolds (or shorty header replacements) to the factory single outlet exhaust? Just a fabricated Y pipe? Is the problem the cats that are in the Y pipe (I haven't looked at the exhaust too close so I'm not sure how it's layed out)?

Never mind, Looks like I found my own answer. Need to clearance the transmission case, which is a deal breaker in my eyes.

Yup, not an easy swap, otherwise I'd also have them... plus Jeep SRT manifolds are in high demand as an upgrade on LX cars and next to impossible to find used. They are very costly for a new set from the stealer.